The long range objective of this project is to develop a line of products for vascular embolus detection. Currently, no way exists to dynamically monitor, detect, or record vascular embolic events. The specific aim of Phase I will be to test and improve a prototype automatic embolus detector by in vitro studies of hydrogen bubbles and microbeads flowing through Tygon tubing and to test its usefulness during cardiopulmonary bypass by monitoring the arterial line from the extracoporeal pump. In Phase II, we will develop a dedicated instrument for commercialization and further define the numbers and sizes of emboli as well as to further explore clinical applications. The instrument promises to significantly improve the prevention and treatment of embolic sequelae of various medical conditions by: a) specifying microembolization in patients presenting with predisposing conditions, b) guiding the use and determining the effectiveness of various therapies such as anticoagulants and cardiovascular surgery, c) expanding the knowledge of stroke and other vascular embolic disorders.